Recycled cement

Wang, Junjie; Mu, Mulan; Liu, Yongliang

doi:10.1016/j.conbuildmat.2018.09.181

Cited by 134 publications

(75 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The catalyst cannot be regenerated or recovered and must be neutralized then removed right after the completion of reaction. This will eventually generate a large amount of wastewater during the purification stage [9]. Furthermore, the separation process of homogeneous catalysts from products is challenging and tedious.…”

Section: Biodiesel Productionmentioning

confidence: 99%

“…There are 180 million tonnes of shattered concrete generated from construction sites annually. Hence, these cement waste can be transformed into useful item instead of dumping them as a waste [9]. The cement-based waste is considered a promising calcium sulphate source due to its high conversion rate and the presence of metal oxides which further enhance the catalytic activity of the triglycerides alcoholysis in biodiesel production [2].…”

Section: Heterogeneous Catalyst Derived From Construction Wastementioning

confidence: 99%

“…The construction waste is a pertinent concern in protecting the environment. Taiwan has generated approximately 1.27 million tonnes of construction waste in 2009 [9]. The construction waste contains a wide-ranging proportion of municipal solid waste.…”

Section: Introductionmentioning

confidence: 99%

“…The most common method to dispose construction waste is by landfilling. Hence, the potential to apply of using construction waste as the derivation for heterogeneous catalyst for the production of biodiesel can provide a cost-effective approach to recycle the waste and eventually can reduce the production cost for the biodiesel production [9].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

A review of heterogeneous calcium oxide based catalyst from waste for biodiesel synthesis

et al. 2019

View full text Add to dashboard Cite

Biodiesel is one of the most promising method to replace the fossil fuels because it is more environmentally friendly. Nevertheless, biodiesel manufacturing costs are much higher compared to conventional fossil fuels. Thus, the biodiesel should be synthesizing from reusable wastes to minimize the production cost. Homogeneous catalyst is the most common catalyst employed in the commercial biodiesel field. However, there are some drawbacks in using homogeneous catalyst in the reaction such as the difficulties faced in separation process of the homogeneous catalyst from the mixture of product. The presence of promising current technology has proved that the utilization of heterogeneous catalyst can assist in overcoming the existing problem of homogeneous catalytic reaction, especially in wastewater generation. The heterogeneous catalysts are more environmentally friendly, easier to separate and its reusability property. Despite its low production cost and its beneficial use as an eco-friendly waste recycle method, waste materials may possess qualities and characteristics that differ from the conventional homogeneous catalyst prior to biodiesel production. This review paper focused in the recent discovery of the heterogeneous catalyst synthesized from natural bio-waste materials, especially CaO-based such as eggshells, seashells and bones for biodiesel production. Apart from that, gypsum, part of the construction waste is proposed as the newly found heterogeneous catalyst. Gypsum exists abundantly due to the rapid development of the economics where construction and demolition activities are happening daily. The utilization of these construction waste-based catalysts may able to provide a sustainable route for biodiesel production. This review will enhance the development and existing scientific data in the area of biodiesel production and the synthesis of CaObased catalyst especially the synthesis of CaO-based catalysts from construction material.

show abstract

Section: Biodiesel Productionmentioning

confidence: 99%

Section: Heterogeneous Catalyst Derived From Construction Wastementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A review of heterogeneous calcium oxide based catalyst from waste for biodiesel synthesis

et al. 2019

View full text Add to dashboard Cite

show abstract

“…In the process to treat the recycled aggregate, some fine powders including cement paste, sand, and coarse aggregate powder are produced, and some studies focused on the quality improvement and application. Increasing the particle size of recycled cement powder with 450 • C treatment and partially replacing the cement powder with ground-granulated blast-furnace slag could effectively improve the quality of recycled cement [7]. Xuan and Shui [8,9] reported that new calcium silicate hydrate (C-S-H) was formed and the optimum temperature was at 700-800 • C. Splittgerber and Mueller reported that clinker could be reproduced from cement paste by 1450 • C thermal treatment [10].…”

Section: Introductionmentioning

confidence: 99%

Study on Properties of Waste Concrete Powder by Thermal Treatment and Application in Mortar

Sui

Liu

et al. 2020

Applied Sciences

View full text Add to dashboard Cite

Waste concrete must be crushed, screened, and ground in order to produce high-quality recycled aggregate. In this treatment process, 15–30% waste concrete powder (<0.125 mm) can be generated. Hydration activity and the reuse of waste concrete powders (WCPs) were studied in this work, and the results illustrated that the particle size changed after a series of thermal treatments at temperatures from 400 ℃ to 800 ℃. The particle size of waste concrete powder decreased by 700 ℃ thermal treatment, and by 600 ℃ thermal treatment, it increased. More active elements appeared in WCP heated by 800 ℃. Nevertheless, the activity index (AI) of WCP, measured by the ratio of mechanical strengths between mortar with a 30% replacement of the cement with WCP and normal mortar without WCP, indicated that the WCP by 700 ℃ thermal treatment had an optimal AI value, which meant WCP treated at 700 ℃ could be used in mortar or concrete as an admixture.

show abstract

Entwicklung thermisch‐mechanisch aktivierter Betonbrechsande als Betonzusatzstoff – Projektvorstellung und erste Ergebnisse

Höffgen

Vogel

Blask

et al. 2023

Beton und Stahlbetonbau

View full text Add to dashboard Cite

Angesichts verknappender natürlicher Primärrohstoffe und gleichzeitig steigender Bauschuttmengen rückt die Schaffung geschlossener Stoffkreisläufe durch ein verbessertes Recycling von Betonabfällen verstärkt in den Fokus aller am Bau Beteiligten. In deutschen Bauschuttaufbereitungsanlagen wurden im Jahr 2020 etwa 47 Mt mineralische Bau-und Abbruchabfälle aufbereitet, von denen sortenreiner Beton (ca. 24 Mt) etwa die Hälfte ausmachte [1]. Aufbereitete Abbruchabfälle werden als rezyklierte Gesteinskörnungen in vielen Anwendungsbereichen verwendet, wobei jedoch der Einsatz außerhalb des Betonbaus überwiegt [2]. Ein geschlossener Stoffkreislauf, wie ihn die DAfStb-Richtlinie für Beton nach DIN EN 206 in Verbindung mit DIN 1045-2 [3] bereits ermöglicht, wird seltener verfolgt. Als Hindernisse gelten logistische Herausforderungen und insbesondere im Vergleich zu primären Gesteinskörnungen veränderte Materialeigenschaften. Speziell die Verwendung von feinen Betonbrechsanden kann sich negativ auf die Frisch-und Festbetoneigenschaften auswirken. Rezyklierte Gesteins-körnungen bestehen stofflich aus porösem hydratisiertem Zement bzw. Zementstein und ursprünglicher Gesteinskörnung, deren Anteil mit kleiner werdendem Korndurchmesser sinkt [4]. Der Anteil hoher Feinstoffmengen mit Korndurchmessern D < 2 mm lässt sich bei der Aufbereitung von Betonabfällen nicht vermeiden und beträgt bis zu 45 M.-%. Eine Kreislaufführung dieser sog. Betonbrechsande wird auch durch die neue E DIN 1045-2:2022-07 voraussichtlich nur eingeschränkt möglich sein.

show abstract

Recycled cement

Cited by 134 publications

References 27 publications

A review of heterogeneous calcium oxide based catalyst from waste for biodiesel synthesis

A review of heterogeneous calcium oxide based catalyst from waste for biodiesel synthesis

Study on Properties of Waste Concrete Powder by Thermal Treatment and Application in Mortar

Entwicklung thermisch‐mechanisch aktivierter Betonbrechsande als Betonzusatzstoff – Projektvorstellung und erste Ergebnisse

Contact Info

Product

Resources

About